feat(ui): render application templates as Vue views mounted before wiring

Templates listed in build/applicationViews.js expand to mount hosts, and
mountApplicationViews() renders them before translation and wiring. Markup
tests read the page through a server-side render helper, the i18n scanner
reads view templates, and Vue preserves whitespace so views keep the exact
DOM. No template is converted yet.

build/vueOptions.js

@@ -0,0 +1,11 @@
+/**
+ * Template compiler options shared by the browser build, the boundary check
+ * and the unit-test loader. Whitespace is preserved so a view renders exactly
+ * the DOM its static markup did: inline layouts depend on text between nodes.
+ */
+export const VUE_COMPILER_OPTIONS = Object.freeze({ whitespace: 'preserve' });
+
+/** `@vitejs/plugin-vue` options for application builds. */
+export const VUE_PLUGIN_OPTIONS = Object.freeze({
+  template: { compilerOptions: VUE_COMPILER_OPTIONS },
+});